TY - JOUR
T1 - Alterations in cultured fibroblasts of sibs with an infantile form of a free (Unbound) sialic acid storage disorder
AU - Thomas, George H.
AU - Scocca, Jane
AU - Libert, Jacques
AU - Vamos, Ester
AU - Miller, Carol S.
AU - Reynolds, Linda W.
PY - 1983/5
Y1 - 1983/5
N2 - Cultured fibroblasts from two sibs with generalized hypertonia, hepatosplenomegaly, and psychomotor retardation within the first year of life were found to have unusual morphologic features. When examined by phase microscopy, the unstained and unfixed cells contained a large number of vacuolated structures whose gross appearance resembled that of a honeycomb in the cell cytoplasm. Electron microscopy studies, following fixation, showed the “honeycombing” to be the result of numerous, closely packed, cytoplasmic, membrane-bound vacuoles. In some of these structures the remains of fibrillogranular material could be detected. Biochemical analysis of crude sonicates of these cells revealed increased levels (4-7 × N) of an acid soluble component that reacted with thiobarbituric acid. Analysis of trimethylsilyl derivatives of this material by gas liquid chromatography and mass spectrometry showed it to be indistinguishable from sialic acid (N- acetylneuraminic acid). Quantitation of this material from the cells of one of the sibs after isolation on a Dowex column yielded 39.8 nmoles of free (unbound) sialic acid per mg protein whereas normal fibroblasts had 1-2 nmoles per mg. Bound sialic acid levels were at the upper limits of normal (24.8 versus 11-23 nmoles per mg protein). The concentration of cytidine monophosphate-sialic acid was normal. After incubation of the patient’s fibroblasts with [3H]-Ar-acetyl- mannosamine for 72 h, there was a 7-fold increase (compared to normal fibroblasts) in the amount of radioactivity in free sialic acid present in the acid soluble fraction. The amount of labeled, bound sialic acid in the acid-insoluble pool, however, was the same in both patient and control fibroblasts.
AB - Cultured fibroblasts from two sibs with generalized hypertonia, hepatosplenomegaly, and psychomotor retardation within the first year of life were found to have unusual morphologic features. When examined by phase microscopy, the unstained and unfixed cells contained a large number of vacuolated structures whose gross appearance resembled that of a honeycomb in the cell cytoplasm. Electron microscopy studies, following fixation, showed the “honeycombing” to be the result of numerous, closely packed, cytoplasmic, membrane-bound vacuoles. In some of these structures the remains of fibrillogranular material could be detected. Biochemical analysis of crude sonicates of these cells revealed increased levels (4-7 × N) of an acid soluble component that reacted with thiobarbituric acid. Analysis of trimethylsilyl derivatives of this material by gas liquid chromatography and mass spectrometry showed it to be indistinguishable from sialic acid (N- acetylneuraminic acid). Quantitation of this material from the cells of one of the sibs after isolation on a Dowex column yielded 39.8 nmoles of free (unbound) sialic acid per mg protein whereas normal fibroblasts had 1-2 nmoles per mg. Bound sialic acid levels were at the upper limits of normal (24.8 versus 11-23 nmoles per mg protein). The concentration of cytidine monophosphate-sialic acid was normal. After incubation of the patient’s fibroblasts with [3H]-Ar-acetyl- mannosamine for 72 h, there was a 7-fold increase (compared to normal fibroblasts) in the amount of radioactivity in free sialic acid present in the acid soluble fraction. The amount of labeled, bound sialic acid in the acid-insoluble pool, however, was the same in both patient and control fibroblasts.
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U2 - 10.1203/00006450-198305000-00001
DO - 10.1203/00006450-198305000-00001
M3 - Article
C2 - 6856393
AN - SCOPUS:0020584111
SN - 0031-3998
VL - 17
SP - 307
EP - 312
JO - Pediatric research
JF - Pediatric research
IS - 5
ER -